The present invention is directed to a method for manufacturing an optical coupling device having a mixer element with an end face and a bundle of glass fiber optical waveguides which have a minimum of spacing therebetween and have their end faces optically connected to the end face of the mixer element.
An optical coupling device, which has a bundle of optical fibers with thin end faces in contact with an end face of a mixing element, is disclosed in U.S. Pat. No. 3,847,781. This coupling device employs a rod-shaped cylinder mixer element of transparent material having an end face on which a bundle of optical waveguides such as glass fibers contact. The optical signal emitted from one of these optical waveguides into the mixer element is reflected by a mirrored surface on the opposite end face of the mixer element and if the element has a desired selected length, will be fed into the individual optical waveguides of the bundle. With such an optical coupling device, it is desired that the individual optical waveguides of the bundle lie next to one another without any intermediate space in order to keep the coupling losses as low as possible. The cladding, which surrounds the individual light waveguides of the bundle and serves the purpose of keeping the optical signal in the optical waveguide from leaving the waveguide, must therefore at least in the region of the optical coupling device be designed to be as thin as possible.